This invention relates generally to a portable system for administering anesthetics to a patient at a location remote from the traditional hospital operating room. There has been a long felt need for a simple, reliable, effective portable anesthesia machine which could be easily operated at a site where health care or emergency services need be provided where the procedure is not complex but may necessarily require administration at a remote location. Typically, for example, dentists have found it necessary to have access to anesthetic services for such procedures as the extraction of wisdom teeth. Similarly, the need has arisen for anesthesia to be administered to victims of earthquakes, floods, hurricanes and the like under emergency conditions and in locations remote from an established health care facility. Also, the military recognizes the benefits of having a truly portable anesthesia rebreathing system. Also, there exists an economic incentive to develop such a system simply because more procedures may be performed in a doctor""s office or on an out patient basis, thus reducing costly hospital charges.
Heretofore, however, anesthesia machines have required a source of electrical power as well as anesthesia gas and oxygen or air. Thus, the portability of such units has been significantly limited in the past. Also, the traditional anesthesia units have suffered from the prospect of cross-contaminating patients by virtue of the fact that the CO2 removal system has been made up of a large canister of soda lime used sequentially for patient after patient. Thus, in those environments where there is an epidemic, the use of anesthesia may contribute to the spread of infection. Cross contamination in the present system is eliminated because the unit uses a single, easily disposable, canister containing CO2 absorbent. Moreover, the simplicity of the present invention allows for the easy cleaning and sterilization or disposal of any part that is contacted by the patient expired gas. The disposable CO2 absorbent canister is the subject of U.S. Pat. No. 5,558,088 of Charles A. Smith, the inventor of the instant invention.
The present invention is directed to an improved anesthesia system which typically functions as a closed system and overcomes many of the shortcomings of the prior art systems. The present invention is a portable anesthesia administering system comprising tubes or conduits to and from a patient, operatively connected to a unit, which provides regulated, pressurized, anesthesia gas. The unit includes a frame having an upper and lower face and supporting structure therebetween defining a container space, said upper face containing a plurality of orifices each accepting an operating element of said unit therein with said elements projecting into the container space. One of said orifices receives a disposable carbon dioxide absorber supported by said upper face and is operably attached in flow communication with said conduits.
A second of said orifices receives and contains a charcoal absorber scavenging unit in flow communication with and downstream of an airway pressure limiting valve. A third of said orifices receives and contains an oxygen pressure gauge and regulator, said gauge/regulator being operably attached in flow communication with an in coming oxygen line. The unit also includes an alarm which is activated by a drop in oxygen pressure below a pre-selected level. A fourth one of said orifices receives and contains an oxygen flush control actuator which permits flushing of said system with oxygen from said oxygen line. A fifth of said orifices receives and contains an airway pressure gauge connected in flow communication with said system thereby providing continuous monitoring of the pressure within the system.
The system also includes an anesthesia vaporizer and regulator mounted on said lower plate and extending into said container space connected in flow communication with said conduits through a manifold block to provide a gaseous anesthesia agent such as Sevoflurane, produced by Abbott Laboratories, Inc. in pre-selected amounts from a self contained internal reservoir of said agent, said manifold block being supported by and in flow communication with said disposable carbon dioxide absorber and including a body having an interior gas containing space a portion of which functions as a mixing chamber.
The body has a plurality of conduits in flow communication with said space for channeling anesthesia gas to and from a patient and providing flow communication to a plurality of anesthesia regulating and control elements. One of such said conduits terminates in a port which permits flow communication with said airway pressure gauge. A second of said conduits terminates in a port permitting a flow communication with an external breathing bag for assisting the breathing of the patient. A third conduit terminates in a port permitting flow communication with an airway pressure limiting valve and a fourth conduit terminates in a port permitting flow communication with said oxygen pressure sensor. Fifth and sixth conduits are in flow communication with inlet and outlet flow control valves connected in line with said breathing tubes. Seventh and eighth conduits are in flow communication with inlet and outlet terminals of the carbon dioxide absorber. A sixth of said orifices receives and contains a fresh gas outlet connected to said anesthesia vaporizer and regulator which provides a source of anesthesia gas. In addition air is introduced through a fresh gas line to a fresh gas inlet port in said block so that both oxygen and air are available at all times if needed. The above combination of elements provides a self contained portable unit. Also advantageously the upper plate may contain an orifice for receiving and storing a second disposable carbon dioxide absorber positioned and adapted to receive the manifold block to provide continuous operation of the system and yet avoid cross contamination in the sequential treatment of patients.
It should be noted that the portable anesthesia unit of this invention is self contained and requires no electrical power source but only a single oxygen gas hose line and preferably a single air line, either one or both of which can be run from an independent tank or other source located a considerable distance away from the anesthesia unit itself. This feature gives a considerable advantage to the versatility and mobility of the unit since frequently it may be in a situation in metro disaster environments where it is not feasible to move large oxygen or air tanks into the immediate vicinity of patients requiring anesthesia.